A construction generally conducted on a road relates to a new road construction, a maintenance construction cutting and eliminating part or all of a conventional paved road and an excavating construction for burying underground a water and sewage conduit, a gas supply pipe or a communication cable at a road.
In terms of a burying construction of a water and sewage conduit or a gas pipe which is a representative one among many construction types, a road paved with asphalt concrete, concrete, block, etc. is cut by a certain width, and the paved section between the cut sides is removed, thus performing an excavation work. An excavation work is conducted until a certain depth, and sand is poured into the excavated portion and a water and sewage conduit or a gas pipe is buried and a good quality soil is covered thereon to reach a certain height. After that, aggregate is paved to make a freezing prevention layer and a pavement material such as asphalt concrete, concrete or block is paved thereon, thus finishing a pavement restoration work.
In the middle of the earlier-mentioned construction, people or vehicles are guided to walk or run on a section where a paved section is removed for construction or a section where a pavement restoration is not finished while a burial construction of a conduit or a cable is finished. In terms of the current construction method, a safety facility such as a safety fence, a rubber cone, etc. is installed at both sides of an excavated section, and the section where a burial construction is finished is temporarily paved with aggregate to have a height higher than a pavement height before construction, and a temporal material such as a nonwoven fabric and a wooden plate is covered thereon, thus making people or vehicle walk or run thereon. The section where a pavement is removed for construction does not have any safety facilities, so people or vehicles are free to walk or run; however in the earlier mentioned method, a section for a pedestrian passage or a vehicle passage is made narrower, which leads to interfering with the flow of people or vehicles. Since a temporal material can be easily destroyed, the ground can be exposed, thus generating a lot of dusts. The ground might become protruded owing to the subsidence or erosion which generally occurs since people or vehicles repeatedly walk or run thereon or by means of rain, thus causing accidents of people or vehicles. Since the section from which the paved section is removed for construction does not have any safety means, it might be dangerous. The compensation or law suit due to the accidents delays the construction.
The temporal materials such as a nonwoven fabric or a wooden plate are not able to prevent the input of rain in a construction site when it rains, so the water content of the earth increases, which make impossible the ground tramping work. Part of the construction site might be subsided or eroded, thus forming a groove or a water puddle. The earlier-mentioned temporal materials are not good for the safeties of differential settlement sections, and since they are not visually visible at night, the accidents to people or vehicles might accordingly increase.
The temporal materials installed at the removed paved section might be easily torn away as people or vehicle repeatedly walk or runs thereon, so the aggregate or ground surface is exposed, thus generating a lot of dusts. In the event that a long time is needed until the pavement restoration, maintenance works are frequently needed, so over consumption of workers and materials increase, and the construction sites are dirty, which make a city environment look unclean.
The installation of the manhole connecting the underground space and the aboveground space is necessary, which enhances the functions of an underground-buried facility and the maintenance in terms of a variety of road constructions.
In the event of the evacuation work, an evacuation width is determined by considering the kinds of an underground-buried facility such as a water supply conduit and a sewage conduit, the standard and type of a manhole based on the size (diameter) of the underground-buried facility, the burying depth based on the distance from the aboveground, the condition of a road where a burial facility is installed, and a work stability.
The types of the evacuations of the manhole parts are diversified. The cover of the manhole mounted on the top of the manhole is not always mounted at the same position. Its position is determined based on the position and direction of the installation of the manhole, so it is hard to provide a customized cover of the manhole, which causes the lack of a management and a safety measure, thus resulting in more accidents near the manhole. The accident happening near the manhole might bring in a big accident, so a proper measure to such accident is urgently needed.
As described earlier, the aggregate constructed higher than the conventional paved road is needed to be removed depending on the depth of the pavement during the pavement restoration, so the pavement restoration should be performed by paving a pavement material in a state that the ground is fully tramped using equipment such as a roller and a rammer. At this time, the removed aggregate is hard to recycle, thus causing a lot of material consumption. The construction costs a lot since more equipment and workers are provided. In the case of the center of the city, the restoration should be finished within one day. In this case, the pavement restoration costs a lot in the event that the construction section is short, so a construction company might have a lot of financial burden.
Even when the pavement section to be paved is fully tramped, subsidence might occur due to additional tramping work as subsidence naturally occurs or vehicle repeatedly runs on the road after the pavement is finished. In particular, the ground near the cut section of the road is weak for a tramping work, almost construction defects occur at the sections. When a construction defect occurs, additional maintenance is needed, which leads to increasing the cost of construction.
A temporal pavement is performed to reduce the construction defects which occur due to the secondary tramping work. In case of the temporal pavements, since it is needed to remove the temporal pavement materials for a main pavement, a lot of construction wastes occurs, which results in a lot of resource consumptions and environment destruction, thus consuming nation's finance.